Element 115

Sammanfattning: This thesis is devoted to detailed studies of element 115 decay chains using the highly efficient multi-coincidence alpha, electron, gamma and X-ray detector setup TASISpec at the gas-filled separator TASCA at GSI, Darmstadt, Germany. In a three-week long experiment thirty new decay chains assumed to stem from element 115 isotopes were observed together with the very first detections of gamma rays and potential X-rays from these nuclei. Paper I describes preparations in terms of optimisations of the magnetic fields in TASCA. Paper II presents data from 23 of the observed chains and the very first level schemes along element 115 decay chains, and discusses the first observation of potential X-rays. In Paper III aspects of the data analysis are described. Paper IV considers correlations along element 115 decay chains and a generalisation of a previously devised test for congruence of data sets. Paper V presents the remaining seven chains from our experiment and discusses possible isotopic origins of those chains as well as similar chains observed at the Joint Institute for Nuclear Reactions, Dubna, Russia and Lawrence Berkeley National Laboratory, Berkeley, USA. Paper VI is a popular science article about new chemical elements.